Blank for forming collapsible tubes



June 4, 1940. P wlTTE 2,203,376

BLANK FOR FORMING ooLLAPslBLE TUBES original Fifled March 16, 193s j, fef@ W vu MM 5? BAUL M'TTE.

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4Patented June 4, 1940 vraul witte, New Minoru Metal Manufacturing `N.J., assignor to White Company, Hoboken,

N. J., a corporation of New Jersey Original application March 16, 1938,Serial No.

198,163, now Patent No. 2,172,745, dated September 12, 1939.

Divided and this application June 30, 1939, Serial No. 282,052 l 2Claims. (Cl. 29-148) The present application is a division of myapplication Serial No. 196,163, filed March 16, 41938 now Patent No.2,172,745, 'September 12,

My present applicationrelates tp `a blank or slug of soft' ductilematerial suitable for forming into a collapsible tube byV extrusionunder pressure.

Collapsible tubes for containing pastes, such as lo tooth paste, shavingcream and similar materials, are formed of very soft ductile metals,such as tin and lead, or alloys of suclf metals. Informing a collapsibletube, a slug or blank of a soft metal or alloy is placed in a hollow dieof the outside l diameter of the tube to be formedand recessed to thedimensions`I and shape of the neck and v shoulder of the tube.Thereupon, an inner plunger, or inner die, of the internal shape anddimensions of the tube to be formed, is forced 20- against the blank orslug and into the hollow die. As the inner die member is forced into thehollow die, it compresses the slug'flrst into the space between the diesand then, upon further movement of the inner die, causes some of themetal 251:0 flow through a narrow space or slot between the dies andthence over the inner die in athin, seamless sheet to form'the tube-likebody, some of the metal being left in the die to form the shoulder andneck. The body of the tube thus V30 formed is very thin, being only afew thousandths.

of an inch in thickness, andthe shoulder and neck portions are somewhatthicker..

Blanks for forming. such tubes have heretofore for the neck andshoulders of the tube, but for the thin seamless tube-like body that isforced or extrudedfrom the die, and inasmuch as there is some variationin a cast slugor blank, some 40 excess thickness must be permitted inorderto ensure a tube of suiiicient length. When ,a solid disc or blankis used, it is contacted ilrst by a projecting tip of the inner diewhich forms the inner opening of the neck. The effect of 45 vthis is todisplace a corresponding amount of \the metal of the disc while itremains unconflned in the die and thus further to distort the blank or Idisc and render it of uneven or unregulated thickness. I f' 50` In myApresent inve tion I provide a 'disc havingla central opening 7or recessof approximately the diameter of the neck part of the inner die so as toavoid any substantial extrusion of the metal as this part of the innerdie enters ,the .I outer or recessed die and before the metal is beencast in the form of discs, the thickness of 35 the disc being sufficientto 'provide metal not only confined within the two dies. Moreover. Iprovide a blank thatis machined to an accurate thickness and independentof any inaccuracies in casting, and which has a face to fit accuratelyinto the bottom or bottom edges of the outer die. '5

The various features of my invention are illustrated by way of examplein the accompanying drawing, in which Fig. 1 is a section taken on adiameter of the disc. i0 Fig- 2 is a vertical section of a casting moldin which the metaLto form the blahk is cast.

Fig. 3 is a view similar to Fig. 2 showing the blank being machined toan accurate predetermined thickness.

Fig`. 4 is a view showingthe expulsion or removal of the blank from themold, and

Fig. 5 is a view on a smaller scale showing the blank in position in theouter or recessed die of an extrusion machine immediately before beingextruded and formed into a tu v In the example of the invention shown inthe accompanying drawing, the blank III is formed -in the shape of athin circular disc having a central opening II, and a lower face ,I2 theperlph- 25 eral edge ,of whicnis inclined or rounded up" wardly as at I3tothe peripheral face Il. -Each of .the faces II, I2, I3 and Il isformed by casting the metal into a smooth surfaced, accuratelydimensioned mold. An upper face Il, parallel to the face I2, is formedby machining the upper part of the blank to remove any unevennessfromthesurface of the blankv and to reduce it to a predetermined andaccurately gauged thickness. This is obtained by one or more machiningsin which thecast metal is lifted from its mold to a predetermined heightrelative to the cutting edge of a tool that planes 4away the excessmetal as described in my Patent 2,172,745.'

The resulting -blank is one of accurately gauged 40 -thickness with theedges atathe periphery and at the central opening sharply and accuratelyshaped except for the rounded edge `I3 which is tol lit, against theinner surface of an extrusion die.

'I'he manner of forming the blank is illustrated in Figs. 2, 3 and 4 inwhich F1g.2 shows the blank I0 cast into a mold comprising an outerwall.

I6 having a cylindrical ope ng in whichv ts a plunger I1. The plunger Iforms the bottom 50 of thel mold of which I6 forms the peripheral wall Apost station I8 stationary with respect to the wall I6 and of no greaterheight, is positioned centrally of the-plunger I1. I There is thusformed an annular recess into which the molten ASIS after the plungerI'I is lifted or raised, pushing the blank I0 upwardly so that its uppersurface 'is above the upper surface of the wall I6 and post I8.Thereupon a cutting blade I9 passes over the disc, trimming away theupper surface portion 26 of the cast blank and forming the .machinededge I5. It will lbe, understood that the machining may take place withtwo cuts in order to obtain a smoothly machined surface and an accuratethickness 'of the blank. When the machining has been completed, theplunger I 'I is lifted still further to clear the upper surface of thewall I6 whereupon the blank Ill is pushed to one side and is ready forextrusion.

An example of the relation of the blank I6 to the extrusion apparatus isshown in Fig. 5. Inl this figure the blank III is placed in a lower orrecessed die 2| having a cylindrical recess 22, the lower part of whichis sloped at 23 to correspond to the shoulder portion of a tube to beformed, and having a. lower cylindrical recess 24 corresponding to theneck-of the tube.- 'I'he disc I0' is positioned in the extruding recesswith the inclined or rounded edge I3 fitting the inclined edge 23 of thedie recess. .then brought downwardly from V*the position shown in Fig. 5into the recess of the die 2l.

`, recess. Depending from the lower end of the frusto-conical surface 2lis an extension or post 26 adapted to lit into the recess 24 with aclearance corresponding to the thickness of the neck of the tube.

As the plunger 25 is forced into the die recess in which the blank I@ isplaced, the neck projecaeoasvc metal is poured to form the blank I6.'There- The plunger' die 25 is tion or post 28 passes into the centralopening I of the blank.' .The opening II need not be of th exactdimension of the part 26, but is suilicientl close to the dimension astoavoid 'displacemen of any considerable metal until the plunger 2 is in aposition to confine the metal of the blan I6. As the plunger 25 movesinto the reces: therefore, it presses the metal against the Vin clinedwalls 23 until the cylindrical part 26 enterg or is about to enter, thecylindrical wall of th recess 22. Inasmuch as the post 28 enters thiopening II, there is no substantial displacemen of any metal from onepart of the blank to an` other until the metal is confined and thecylin' drical part 26 enters the die recess. Thereupox the pressurecausesthe metal to flow in thi minute slit between the plunger 25 andthe recessed edge, and to move upwardly over the wal lof the plunger,forming the body of the tube.

Owing to the accurate formation of the blank and to the provision of theopeningvII, the extrusion takesl place from a b1ank in which metal hasnot been forced from one part of the blank to another unconi'lned partand there is, therefore, no irregularity in the blank at the time it isconfined by the plunger and thento be extruded from the recess.Consequently, th'e formation of the wall of the tube is uniform andaccurately gauged and a blank of minimum weight or volume may beemployed.

What I claim` is: I

1. A circular collapsible tube blank of soft, highly ductile metal,having parallel flat faces and a central opening, one of said at facesbeing machined to -a sharp edge 'at the periphery and at the opening,and the peripheral edge of the op- 4 posite face being rounded.

2. A collapsible -tube blank of soft, highly ductile metal havinga,central opening and a substantially fiat machined face, a faceopposite said iat face and parallel thereto and having a peripheralmargin inclined to correspond to a shoulder of a tube, and having acentralopening.

PAUL

